To let your users search or filter the data you display on a page you start by adding User Input elements to your page. These elements are where your users will enter the criteria they want to use to search or filter your data. Then you write the code that runs the search or filter.
For example, you could add code to an input box so that visitors can type their search text, or add code to a dropdown list or radio buttons to allow visitors to filter content based on their selection. It's important to remember not to connect your user input element to data when using it as input for searches and filters.
To learn more about creating searches and filters via code, see this article, this video, the wix-data API, and the wix-dataset API.
Tip You can also use input elements to allow visitors to filter content directly in the Wix Editor, without code.